Method for preparing organic isocyanate

• Main Author: XUE YONGHE
• Format: Patent
• Language: Chinese; English
• Published: 17.11.2017
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

The invention provides a method for preparing organic isocyanate. The method comprises the steps that phosgene is dissolved in a low-temperature solvent in an absorber to obtain a phosgene solution, and impurities are removed; purified organic isocyanate is obtained after phosgene analysis, gas phase reaction, quenching absorption, exhaust and washing, phosgene recovery, solvent removal and two-stage refining. According to the method, the one-step high-temperature gas phase reaction is adopted, a complex multi-stage reactor is not needed, and the retention time is shortened from several hours to 3-20 seconds; the procedures are simplified, the investment is saved, the production rate and the yield are increased, and the energy consumption and the production costs are reduced; phosgene is recovered by a reverse absorption method, complex multi-stage cross heat transfer and condensation are not needed, the procedures are simplified, the investment is saved, and the energy consumption and the production costs ar